Ladder Sights on a Lever Action?

[WaddWatsonEllis]

Hi,

I was watching 'The Streets of Laredo' the other day, and Captain Woodrow Call pulls out what looks like a Winchester (Marlin?) lever action and it has a ladder sight a la Spencer and Rolling Block rifle style. What is more interesting was that the rear sight was not mounted on the tang, but where the normal 'buckhorn' rear sight would be mounted.

Was this just another 'Hollywood-ism' or were there actually lever actions around like this one?

I have also pasted this onto the 'Gunsmithing' and 'Historical' Forums as well....